Sr<ifons and Blisters 139 



are applied with a seaton. Seatons are used when a mild, 

 but long -continued counter-irritant is wanted. 



Blisters. — The two substances commonly used for 

 blisters are pulverized Spanish flies (Cantharides) and 

 the biniodid of mercury. The former makes what is 

 commonly known as a "fly -blister." The latter, from 

 its color, is commonly called a "red-blister." These 

 blisters are made by thoroughly mixing one part b}' 

 weight of the drug and eight parts of fresh lard or 

 vaseline. Both of these blisters are poisonous, and 

 should be cared for accordingly. If it is desired to 

 remove bunches, especially bony bunches, the red-blister 

 is commonly preferred ; for ordinary purposes, the fly- 

 blister is used. Neither kind should be applied to a 

 raw surface or over a very large area, for it maj^ be 

 absorbed and prove injurious to the animal. 



The hair should first be clipped from the area, 

 after which the blister is rubbed in with the fingers 

 from three to ten minutes, depending on how severe 

 an irritation is desired. In most cases, a light blister 

 repeated is more effective and more satisfactory than 

 a single severe one. Horses with thick skin re- 

 quire the blister to be rubbed in longer than thin- 

 skinned, nervous ones. The blister should be left on 

 from twenty -four to thirty -six hours, or until a watery, 

 gummy fluid exudes from the skin and sticks the hair 

 together. Then the area should be thoroughly v/ashed 

 with warm water and soap, wdped dry and greased 

 with fresh lard or vaseline. 



If the blister is applied to the hind legs, or to any 

 place which the horse can switch, the tail should be se- 



